People don't like uncertainty. Installing after-market operating systems will always be a hobbyist thing. Not entirely dissimilar to cars: some people will go into the details and even of those not many will customise their vehicle.
Because "the market" is so small, nobody bothers making things that you can buy off the shelf. And when I mean "off the shelf", I literally mean at a physical store you can actually go to and try things.
Having a "developer edition" or a drop down on a website isn't going to move the needle, because you have to know what you're looking for in order for that dropdown to be meaningful.
Once we have a handful of manufacturers actually selling Linux based laptops in stores I think we'll get more adoption, however you can see how strong the stranglehold that these giant companies have on the market when you merely compare AMD to Intel; even now AMD remains a niche CPU in stores despite absolutely trouncing Intel for the last half-decade, and seeing any market penetration in stores took years despite being clearly superior in performance, battery life and temperature - Linux, for many people is not "clearly superior" in such clear cut ways.
It is hardly any different from getting that IoT board, that only works with the snowflake distro that was made available on the release date, and nothing else.
Meanwhile, I know there are plenty who are still using Win7 and below, and there's even a nontrivial community writing drivers for newer hardware and such.